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See detailFifty years of contrasted residue management of an agricultural crop: impacts on the soil carbon budget and on heterotrophic respiration.
Buysse, Pauline ULg; Roisin, Christian; Aubinet, Marc ULg

in Agriculture, Ecosystems & Environment (2013), 167

Crop management exerts a strong influence on the soil carbon (C) balance. This study investigated a long-term experiment initiated in 1959 at a site in the Hesbaye region of Belgium and focused on three ... [more ▼]

Crop management exerts a strong influence on the soil carbon (C) balance. This study investigated a long-term experiment initiated in 1959 at a site in the Hesbaye region of Belgium and focused on three contrasted treatments: residue export (RE), farmyard manure (FYM) addition and residue restitution (RR) after harvest. The objectives were to quantify the components of the C budget of croplands from a 50-year perspective and to identify the impact of the treatments on this budget and soil C sequestration, given the relatively low levels of esidue application. The soil C budget was calculated for each treatment on the basis of total soil organic C (SOC) content measurements and C input data collected since the experiment had begun and drawn from the literature. To evaluate the robustness of this approach, the budget-based output estimates were compared with annual heterotrophic respiration (HR) averages extrapolated from seasonal field HR measurements carried out at the same experimental site in 2010. The soil C budgetbased output estimates accorded well with field-based HR measurements and with most HR estimates in the literature, suggesting that, despite the many uncertainties affecting the soil C budget, these results were robust. The three treatments investigated in this study had different impacts on SOC stocks, mainly during the first 20 years of the experiment. RE and FYM caused significant SOC decreases (on average, −7 ± 5 g C m−2 year−1 over the 50 years) and increases (10 ± 5 g C m−2 year−1), espectively, whereas RR had no significant impact on the SOC stocks. The study also showed (i) the very large part (about twothirds of the total input) that represented the below-ground input, weeds and other left-over residues in the C budget, (ii) the important role probably played by residue quality in C sequestration and (iii) the large proportion of C lost annually rom the soil (which represents 93–98, 100 and 102–107% of the amounts of fresh residue rought to the soil each year in the FYM, RR and RE treatments, respectively). [less ▲]

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See detailFifty years of crop residue management have a limited impact on soil heterotrophic respiration.
Buysse, Pauline ULg; Schnepf-Kiss, Anne-Caroline; Carnol, Monique ULg et al

in Agricultural and Forest Meteorology (2013), 180

The impacts of crop residue management on soil microbial biomass, labile carbon and heterotrophic respiration (HR) were assessed at a long-term experimental site in the Hesbaye region in Belgium. Three ... [more ▼]

The impacts of crop residue management on soil microbial biomass, labile carbon and heterotrophic respiration (HR) were assessed at a long-term experimental site in the Hesbaye region in Belgium. Three treatments, residue export (RE), farmyard manure addition (FYM) and residue restitution after harvest (RR), have been applied continuously since 1959. The soil is a Eutric Cambisol with, in 2010, significantly different total soil organic carbon contents of 4.4, 5.1 and 5.9 kg C m-2 under the RE, RR and FYM treatments, respectively. Manual field HR measurements were carried out during the 2010 and 2012 crop seasons using a dynamic closed chamber system. Microbial biomass, labile C content and metabolic diversity of soil bacteria were assessed in spring 2012. Fifty-one years after the beginning of the treatments, residue management had a limited impact on HR. Based on daily averaged values, the treatment had a significant impact (α = 10%) in 2012 but not in 2010. Based on the individual measurement dates, the treatment impact was less obvious in 2012; with the observation of a significant impact (α = 10%) on HR in only 7% and 36.8% of the measurement dates in 2010 and 2012, respectively. Labile C and microbial biomass were significantly lower in the RE treatment than in FYM and RR. Residue management had no significant effect on cold-water extracted carbon and metabolic diversity of heterotrophic soil bacteria. The limited impact of residue management on HR could be explained by (i) the relatively low amounts of recent above-ground crop inputs, (ii) the large proportion of below-ground residues and other non-exportable above-ground residues reducing the potential differences between treatments and (iii) the relatively large spatial variability of HR. In conclusion, carbon losses due to heterotrophic respiration did not differ between RE, FYM and RR treatments in the studied soil. This contrasts with the different soil organic carbon contents observed in these three treatments after fifty years of experiment. Further investigations regarding the reduction of spatial variability and the potential roles played by organic matter protection within aggregates and biochemical composition of inputs are needed. [less ▲]

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See detailFifty years of landscape evolution in Southwestern Mauritania by means of aerial photos
Niang, A. J.; Ozer, André ULg; Ozer, Pierre ULg

in Journal of Arid Environments (2008), 72(2), 97-107

South-western Mauritania is located in a semi-arid environment exposed to large rainfall variations and affected by a severe drought since the mid-1960s. The studied area includes the right bank of the ... [more ▼]

South-western Mauritania is located in a semi-arid environment exposed to large rainfall variations and affected by a severe drought since the mid-1960s. The studied area includes the right bank of the Senegal River and the southern extension of the Saharan sandy dunes and is based on the analysis of climatic data, field studies, and four aerial surveys realized since 1954. The climatic analysis shows that, after a strong decline of yearly rainfall started in the mid-1960s, a significant increase is observed from the early 1990s. In the meantime, dust storms frequency has dramatically increased while the threshold wind speed declined as a result of vegetation contraction. The comparison of the four mosaics of aerial photos reveals the major impact of both drought and human on recent environment changes with the strong decline of the forest, the reactivation of sandy soils and the apparition of large rice fields. If the increase of active dunes activity is likely to be a consequence of the persisting drought, forest decline is more likely to be attributed to fuel wood collection in a first time, then to the creation of rice fields since the late 1980s. Although the 2003 aerial photos show a timid return of vegetation in very limited and specific areas, field surveys show that wind erosion is still very important and water erosion is developing very rapidly because of the absence of vegetation cover. (C) 2007 Elsevier Ltd. All rights reserved. [less ▲]

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See detailFifty Years of Quasars. From Observations to Physical Parameters
D'Onofrio, Mauro; Marziani, Paola; Sulentic, Jack W. et al

in D'Onofrio, M. (Ed.) Fifty Years of Quasars: From Early Observations and Ideas to Future Research (2012)

Observational measures of AGNs allow us to directly infer some basic physical properties of quasars including (1) physical conditions and chemical abundances in the broad-line emitting gas as well as (2 ... [more ▼]

Observational measures of AGNs allow us to directly infer some basic physical properties of quasars including (1) physical conditions and chemical abundances in the broad-line emitting gas as well as (2) radius of the line-emitting region, (3) black hole mass, (4) and Eddington ratio. In this chapter, we seek information on how these quantities are measured. One of the surprises of recent times, that would have shocked the discoverers in the 1960s are the large BH masses and high chemical abundances inferred for even some of the highest redshift quasars known. [less ▲]

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See detailFifty Years of Quasars. Quasars Classes and Their Relationships
D'Onofrio, Mauro; Marziani, Paola; Sulentic, Jack W. et al

in D'Onofrio, M. (Ed.) Fifty Years of Quasars: From Early Observations and Ideas to Future Research (2012)

Most of the questions in this chapter deal with sources that do not show the "classical" broad emission-line spectrum that characterizes the majority of known AGNs at high and low redshift. If that ... [more ▼]

Most of the questions in this chapter deal with sources that do not show the "classical" broad emission-line spectrum that characterizes the majority of known AGNs at high and low redshift. If that majority represents a "parent population" of AGNs, is the apparent absence of broad lines a result of obscuration, orientation, or different physical conditions? Can all of the subclasses be unified under the AGN umbrella? With the unification scheme set in place and assumed to be fundamentally correct, there are at least four overarching questions: do all type-2 AGNs possess an obscured broad-line region? Or how can we distinguishing type-2 AGNs without a broad-line region if they exist? Where is the low end of quasar activity? The least luminous AGNs are the so-called low-ionization nuclear emission-line regions (LINERs), but it is legitimate to ask if they are all true AGNs. [less ▲]

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See detailFighting Poor Quality Medicines: Develop-ment, Transfer and Validation of Generic HPLC Methods for Analyzing two WHO Recommended Antimalarial Tablets
Mbinze Kindenge, Jérémie; Yemoa, Achille; Lebrun, Pierre ULg et al

in American Journal of Analytical Chemistry (2015), 6

As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative ... [more ▼]

As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative techniques. In this study, a generic liquid chromatographic method was firstly devel-oped for the purpose of screening 8 antimalarial active ingredients, namely amodiaquine (AQ), piperaquine (PPQ), sulfalene (SL), pyrimethamine (PM), lumefantrine (LF), artesunate (AS), artemether (AM) and dihydroartemisinine (DHA) by applying DoE/DS optimization strategy. Since the method was not totally satisfying in terms of peak separation, further experiments were undergone applying the same development strategy while splitting the 8 ingredients into five groups. Excellent prediction was observed prior to correlation between retention times of predicted and observed separation conditions. Then, a successful geometric transfer was realized to reduce the analysis time focusing on the simultaneous quantification of two WHO's recommended ACTs in anti-malarial fixed-dose combination (AM-LF and AS-AQ) in tablets. The optimal separation was achieved using an isocratic elution of methanol-ammonium formate buffer (pH 2.8; 10mM) (82.5: 17.5, v/v) at 0.6ml/min through a C18 column (100mm×3.5mm, 3.5 μm) thermostated at 25°C. After a successful validation stage based on the total error approach, the method was applied to determine the content of AM/LF or AS/AQ in seven brands of antimalarial tablets currently marketed in West, Central and East Africa. Satisfying results were obtained compared to the claimed contents. [less ▲]

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See detailFigli di Genitori Gay e Lesbiche: ricerca e counseling clinico
D'Amore, Salvatore ULg

Scientific conference (2014, March 21)

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See detailFigli di un testo minore
Curreri, Luciano ULg

in Curreri, Luciano; Traina, Giuseppe (Eds.) Studi in onore di Giuseppe Papponetti (2013)

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See detailLa figuration de l’écrivain dans les Physiologies
Stienon, Valérie ULg

Scientific conference (2011, May 11)

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See detailFigurations de la mort dans le cinéma d’animation
Tomasovic, Dick ULg

Scientific conference (2003, February 12)

Detailed reference viewed: 15 (3 ULg)
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See detailFigurations et médiogrammes. Les micro-fictions du Petit Bottin des Lettres et des Arts
Saint-Amand, Denis ULg

in Glinoer, Anthony; Lacroix, Michel (Eds.) Romans à clef. Les ambivalences du réel (2014)

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See detailLa figure de la femme dans les opéras de Wolfgang Amadeus Mozart (1756-1791) et de Giuseppe Verdi (1813-1901)
Corswarem, Emilie ULg; Onkelinx, Jean-Marc

Conference (2008, November 26)

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See detailLa figure de la Vierge Marie dans l’histoire des femmes et du féminisme
Delfosse, Annick ULg

in Hieros : Bulletin Annuel de la Société Belgo-luxembourgeoise d'Histoire des Religions (2003), 8

The A. offers to study the place of the Marian figure in the women story. She proves to show various points of view: the masculine cleric authorities’ use of the Virgin as an identification norm imposed ... [more ▼]

The A. offers to study the place of the Marian figure in the women story. She proves to show various points of view: the masculine cleric authorities’ use of the Virgin as an identification norm imposed to the women as well as the claim of these latter to define the Virgin also as an emancipation tool. [less ▲]

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See detailLa figure de Simon Kimbangu
Melice, Anne ULg

Conference given outside the academic context (2011)

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See detailFigure della violenza nella tradizione arturiana in prosa
Morato, Nicola ULg

Scientific conference (2005, November 09)

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See detailFigure politiche del precariato negli anni '70: brevi cenni per una genealogia
Cavazzini, Andrea ULg

in M@gm@ : Rivista Internazionale di Scienze Umane e Sociali (2011), 9,2

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See detailFigurentheater für die Allerkleinsten? - eine Elternumfrage.
Viehöver, Vera ULg

in Das Andere Theater (2011), 21(2011),

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